Fuel-feeding mechanism



C. H. RICH- FUEL FEEDING MECHANISM- Jan. 29, 1929.

Filed Dec. 8, 1925 INVENTOR CARL H. R1011 QQ m ATT NEY WITNESS Patented Jan. 29, 1929.

[VUNETE' stares r orrics CARL H. RICH, OF WORCESTER, MASSACHUSETT S, ASSIGNOR 'IO RILEY STOKER COR- PORATION, OF WORCESTER, MASSACHUSETTS, A CORPORATION OF MASSACHU- FUEL-FEEDING MECHANISM.

Applicationfiled December 8,: 1926. Serial No. 153,372.

This invention relates to automaticstokers, and more particularly to stokers of the type in which a reciprocating ram pushes fuel into the furnace.

In stokers of this typeit is at times advisable to provide means for varying the length of the ram stroke in order to control the rate of fuel feed. Devices have been constructed for this purpose in the past, but certain inherent defects have always existed :in these prior arrangements. For example, one form of construction comprises aconnecting rod pivoted to the ram and arranged to slide through ablock rotatably mounted on a crank of a driving crankshaft. Gollars are mounted on the rod to form abutments against which the block will strike, the outer collar being adjustable along the rodto vary the amount of lost motion and the stroke of the ram. With such an arrangement, the connecting rodis not in line with the force which it transmits, for it passes through the block at one side of the crank bearing. This results 1n an ,GCCGIllZIlC loading of the rod, and as the forces encountered are frequently of great magnitude,

there is serious danger of the rod becoming broken. Moreover, in this type of construction the ram is always pushed in to the same position, and withdrawn to a variable position depending upon the collar adjustment. When this adjustment is made for a short stroke, the ram is at all times largely beneath the hopper, thus greatly increasing the opportunity for coal to arch across the hopper above the ram and fail to drop in front of the ram on its outwardstroke.

In another type of construction, the connecting rod is pivotally joined to a crank of the driving crankshaft and arrangedto slide through a block rotatably mounted on, the ram. Collars are mounted on the rod to limit this sliding movement, the outer collar being joined to the rod by a pin passing through the two members. Several holes are provided in the rod inorder to permit the outer collar to be mounted at various positions along the rod, thus allowing an adjustment of the ram stroke. The adjusting pin is usually relatively weak, and is intended to fail in shear and thus prevent damage to the driving mechanism if the ram encounters an. exceptional resistance. This occurs rather frequently, usually being caused by a block of- Wood, or other foreign material, in the coal. .Since thepin-is located between the ram and the crankshaft in such a construction, it isnecessary to reach over the top of the rotating crankshaft in order to replace the shearing pin or to adjustthe length of stroke of the ram. This 1s not only inconvenient butalso highly dangerous to the operator.

It is accordingly the main object of my invention to overcome such difficulties and to provide a fuel feeding mechanism for a stoker which will drive the ram through an ad ustable stroke and in which the adjusting device is located at a cessible to the operator.

A further object is to construct a stoking mechanism by whichthe .fuel feeding ram may be withdrawnalways to the same point easily acposition and pushed inwardlyto a variable position, whereby the tendency of the fuel to arch over in the hopper is minimized.

Another object is to provide a ram reciprocating mechanism with a safety device comprisinga yieldable member which is so, located that it maybe conveniently and safely replaced without stopping the crankshaft. I j

lVith these and other objects in View, as will be apparent to one skilled in the art, my invention resides in the combination of parts set forth in thespecification andqcovered by the claims appended hereto.

In accordance with my inventionylj provide a stoker ram reciprocating mechanism which has a driver, such as a crankshaft, connected to the ram by means of an adjustable device so arranged that it may be moved to vary the effective fuel feeding effect of the ram. This is accomplished by adjusting the length of the stroke of the ram, and the, parts are preferably so arranged that the ram may be moved outwardly to a fixed positionand inwardly to a variable position so that the rain will be entirely withdrawn from beneath the hopper on the outward stroke and thus obviate the possibility of. 'coal loo a construction may involve an adjustable lost motion connection between the ram and the connectingv rod which is pivotally attached at its other end to the crankshaft, the lost motion permitting the connecting rod to move periodically through a fixed cycle while the ram moves inwardlyonly 'asfar as desired Apr ma y feature of my n ntion is to provide a device which makes it possible to change the relative positions of the adjustable parts of the lost motion connection by means of a control member located at the front of the stoker in a freely accessible position. 'A further feature includes a safety .device arranged to yield under an excessive load on the ram, which may comprise a frangible member, such as a shearing pin, connecting two separate parts, and this frangible member is likewise located in or controlled from an easily accessible position. 7

Referring to the drawings, in which like reference numerals indicate like parts:

Fig. 1 is a sectional side elevation of a stoker comprising one embodiment of my invention, the section being taken through the center of the ram;

Fig.2 is a side elevation of the connecting rod and wrist pin removed from the stoker; and

Fig. 3 is a horizontal section through the center of the ram showing the method of joining the connecting rod thereto.

The embodiment of my invention illustrated in the drawings comprises a suitable driver, shown in the present instance as a rotatable crankshaft 1O, which may be driven from any desired source of power. The crankshaft is mounted in suitable bearings in a gear box 12, which as will be understood contains the requisite mechanism for transmitting power to the crankshaft. The fuel feeding device, driven from this crankshaft, may comprise a fuel hopper 14 located above a ram casing 15 adjacent to the wall 16 of a furnace. Fuel from the hopper falls in the path of a reciprocable ram 18, and is thereby pushed into the furnace. The ram is preferably cylindrical, as illustrated, and adapted to reciprocate in a substantially horizontal oath bein uided in its movement b the surrounding parts of the ram casing 15.

The ram is driven from the crankshaft 10, and the driving connection is preferably so arranged that the effective fuel feeding capacity of the rarnmay'be varied as desired without altering the speed of rotation of the crankshaft. Thisinay be accomplished by suitably varying the length of stroke of the ram, as by means of a lost motion connection which is preferably so arranged as to withdraw the ram to the same position each time, thus providing an ample space into which fuel may fall from the hopper. I preferably utilize a connecting rod comprising two relatively adjustable parts arranged to provide a variable amount of lost motion which may be manually adjusted from the front of the stokermechanism.

In the construction illustrated, one part of theconnecting rod is pivotally connected to the cylindrical crank pin 20 on the crankshaft. For convenience in manufacture and assem bly, this part of the rod comprises a number of separate members, including a box 22 and cap 24; surrounding the crank pin and held together by bolts 28.-

' In order to permit lost motion, the connecting rod is arranged to move relative to the am, preferably by a slidable'joint. For this purpose, the inner rod is suitably attached to the box 2-2, as by screw threads, so that it is rigid therewith. The ram is provided in its interior hollow portion with suitable bosses 32 bored to pivotally receive a wrist pin 33. This wrist pin has a transverse opening arranged to slidably receive the inner end of the rod30. A yoke 35 surrounds the central portion of the wrist pin, being provided with a bore through which the rod 30 may slide. This yoke provides an enlarged bearing surface for the rod and suitable shoulders 36 and 37 by which the ram may be driven.

In order to drive the ram, it is necessary to limit the sliding movement of the connect ing rod relative thereto, and for this'purpose I provide two abutments on the rod. I prefer to arrange a fixed abutment on the inner end of the rod, whereby the ram may be withdrawn to the same position at each rotation of the crankshaft. Such an abutment may be formed by a washer 40 held against a shoulder on the rod by a nut 41. A threaded plug 44 maybe provided in the working face of the ram to permit assembly of these parts. An adjustable abutment is provided to push the ram inwardly toward the furnace through the length of stroke desired. This abutment may be formed by the second part of the connecting rod, adj ustably attached to the first mentioned part. This may comprise a block 45' arranged to slide, for adjustment, on the rod 30 between the box 22 and the yoke 35. v I

' For the convenience and safety of the operator, this adjustment is made at an easily accessible point and preferably from a position in front of the rotating crankshaft, whereby any danger of personal injuries to the operator is eliminated. i For this purpose I arrange a control member or adjusting head 50, which may be slidably mounted on: an

outer rod or post 51 attached to cap 24: and

projecting outwardly therefrom in a direc tion substantially in line with the inner rod 80. This post may have a number of spaced transverse holes 02, and the control member 50. may be located as desired relative to the post by means of an adjusting pin 53, which as will be understood is removed when making an adjustment. It is necessary to connect the control member with the abutment 45, and for this purpose I prefer to utilize two rods 55, one of which passes on each side of the crankpin. By this means the device is made symmetrical, and eccentrio loading is avoided. These rods are Inn shown threaded into block45 and attached to the control memberby nuts 56, and are preferably arranged to slide freely through bores in the boX 22 andcap 24, thus permitting a compact assembly. i 7

It is desirable to provide a member which will yield incase the ram encounters an obthei'ain, the rod 51 tends to pull away from the cap, and the pin 60 is placed in shear. The

pin is so dimensioned that it will yield before the other parts of the mechanism are overloaded. V

The operation of the invention will now be apparent from tlierabove disclosure. Coal or other fuel is placed in the hopper 14-. The crankshaft l0. isrotated by a suitable source 'of power connected to the gear box 12. On

the inward stroke, the rod slides through the yoke and the wrist pin 33 until the block strikes against the yoke, thus causing the ram to push coal into the furnace. On the outward stroke, the connecting rod slides .relative to the rain until the washer 4O ing the pin 53 and sliding the head along the slowly moving rod and then replacing the pin in the desired hole. This is done during the outward stroke of the ram when no force is exerted on the parts to be adjusted, and since they are in front of the crankshaft the adjustment may be made safely and easily. If the pin should shear when an obstruction is met by the mm, a new pin may be easily replaced on the outward stroke of the rain, it being observed that there is a direct draw bar connection 30 between. the crankshaft head and the rain, and that all other parts of the mechanism are freely adjustable at this time. It will therefore be apparent that I have provided a simple construction with freely accessible adjustment parts which may be safely and quickly ZHl'jllSl QCl as desired and which will operate efficiently to move coal into the furnace at the required rate of feed.

laving thus described my invention. what I claim as new and desire to secure by Letters Patent 1S 1. A stoker comprising a reciprocable ram" arranged to feed fuel into a furnace, a driver driver for changing theadjustme'nt of said member.

2. In a stoker, a reciprocableram arranged to feed fuel into a furnace, and a reciprocating mechanism therefor comprising a driving member, means connecting the ram and the driving member which is movable relative to the ram to provide a limited degree of lost motion, and means freely accessible at the front of the stoker to limit the extent ofsuch elative movement and thereby control the length of stroke of the ram.

3. A stoker comprising-a reciprocable ram,

a driving mechanism therefor including a revoluble crankshaft, means connected to said crankshaft to push the-ram inwardly to av variable position and means controllable from a position'm front of the driving crankshaft for adjusting the length of the rain stroke. j j v 4. In a stoker havinga reciprocable ram,;a driving mechanism therefor comprising a driver, a connecting rod betweenthedriver and the ram arranged to slide relative to the ranithrougli a limited degree of lost motion,

and means controllable from a freely accessible position in front of the stoker to limit such sliding movement and so vary the length of stroke of the ram. a

5. In a stoker, a reciprocable ram arranged to feed fuel into a furnace, a driver, a con necting rod between the driver and the ram part being operatively connected to the driver and the other to'the ram and freely accessible means for adjustingtherelative positions of said parts andthereby varying the effective fuel feeding capacity of the rain.

6. In a stoker having a fuel feeding mm,

reciprocable ram, a connecting rod joined to said crankshaft and arranged to slide through a limited degree of lost motion relative to said ram, and means for limiting the sliding movement of the connecting rod relative to the ram, comprising an adjustable member located in front of the crankshaft.

, 8. In a stoker, a rotatable crankshaft, a

reciprocable rain, a connecting rod joined to the crankshaft and arranged to slide relative to said ram, abutments on said rod to limit the sliding movement of the rod relative to the ram, one of said abutments being capa 7 In a stoker, a rotatable crankshaft :a

having two relatively adjustable parts, one

'ble of adjustment, and means for making said adjustment from a position in front of the crankshaft.

. ward stroke, and means adjacent to the crankshaft for controlling the position of said adjustable abutment.

10. In a stoker, arotatable crankshaft, a reciprocable ram, a connecting rod pivotally mounted on the crankshaft and arranged to slide relative to the ram, a fixed abutment adjacent to the inner end of said rod to limit sliding movement of the rod relative to the ram on the outward stroke, an adjustable abutment on said rod to limitv sliding movement of the rod relative to the ram 0n the inward stroke, means to permit said adj ustable abutment to yield if the ram encounters an exceptional resistance, and means adjacent to the outer end of said rod for controlling the position of said adjustable abutment. 11. In a stoker, a rotatable crankshaft, a fuel hopper, a reciprocable ram for feeding fuel from said hopper into a furnace, a wrist pin pivotally mounted in said ram and pro vided with a transverse bore, a connecting rod pivotally mounted on said crankshaft and comprising an inner rod slidable through said Wrist pin and an outer rod provided with spaced transverse holes, a fixed abutment adjacent to the inner end ofsaid inner rod, a block slidable on said inner rod between said Wrist pin and said crankshaft, an adjusting head slidable on said'outer rod, a pin to locate said adjusting head as desired, and means connecting said adjusting head with said slidable block.

Signed at Worcester, Mass, this 6th day of December, 1926.

CARL H. RICH. 

